*{
  margin: 0;
  padding: 0;
  list-style: none;
}
html,body{
  width: 100%;
  height: 100%;
}
.App{
  width: 100vw;
  height: 100vh;
  display: flex;

  .left{
    width: 10%;
    a{
      line-height: 50px;
      display: block;
    }
  }
  .right{
    button{
      width: 50px;
       height: 30px
    }
    .on{
      background: rebeccapurple;
    }
  }
}